[hinkley]

I’ve done the math a couple of times and IIRC if we can get the charge density per kilo to about twice what lithium ion can do, you hit a point where a deposit battery that’s around 20 kilos has enough range extension to start being worth doing. That’s the weight of a large bag of kitty litter or a commercial bag or rice. Put a good ergo handle on it and most people should be able to lift a few of them consecutively.

But until one unit is worth about 8 miles of extended range, there would be no point. 3@25 or 30 miles might make it worth the trouble for a road trip, or camping.

[fooker]

A great range extender weighing twenty kilos is available right now, a diesel generator.

It can also double as a air/water heater, emergency power for household or medical appliances, and emits about as much carbon in 30 years as it takes to manufacture a battery pack.

[hinkley]

Honestly surprised Honda hasn’t designed a hybrid that’s more generator and less hybrid but I suspect that has to do with air and noise pollution loopholes for generators versus engines.

[rsynnott]

Nah, the BMW i3 had one of these as an option, as does some Chinese car, with no regulatory difficulties. Also a common arrangement for ‘hybrid’ buses and trains.

[smileysteve]

The i3 certainly had some us regulatory difficulties, they had to change the battery and fuel tank sizes.